Improved Deadbeat Predictive Current Control of Dual Three-Phase Variable-Flux PMSM Drives With Composite Disturbance Observer

The dual three-phase variable-flux permanent-magnet synchronous motors (VF-PMSM) have received more attention in the variable-speed drive applications since they have advantages of high-efficiency in flux-tuning ability, low current stresses in phase legs and high fault-tolerant capability. The magnetization-state of the permanent magnets in VF-PMSM can be manipulated by the larger d-axis current pulse. However, the accompanied issues of parameter variation and inherent model uncertainty in magnetization manipulation of VF-PMSM increase the difficulty in parameter tuning for conventional proportional-integral controller, which deteriorates the control performance in current loop. To achieve the high performance of current tracking, an improved deadbeat predictive current control (DPCC) with composite disturbance observer has been proposed for dual three-phase VF-PMSM in this article. In the proposed composite disturbance observer, the generalized proportional--integral observer (GPIO) is employed for tracking the time-varying disturbance, and the sliding-mode observer is designed to reduce the settling time caused by the high-order GPIO for the improvement of the system dynamics. The analysis about the bandwidth-parameterized method has been presented for tuning the coefficients of the composite observer. The experimental results are presented to verify the validity of the proposed DPCC with composite disturbance observer for dual three-phase VF-PMSM drives under model uncertainty and different operating conditions.